1. Technical Field
The present invention relates to a pillar structure and a vehicle side portion structure.
2. Related Art
As a pillar structure equipped with an outer panel and an inner panel, Japanese Patent Application Laid-Open (JP-A) No. 2011-251659 discloses a pillar structure where a cross-sectionally hat-shaped outer panel and a cross-sectionally hat-shaped inner panel are joined to one another at flange portions on both end portions. Furthermore, in the pillar structure of JP-A No. 2011-251659, a reinforcement member is disposed between the outer panel and the inner panel, and the reinforcement member is joined at flange portions to both the inner panel and the outer panel.
However, when, during a side impact to the vehicle to which this pillar structure is applied, the impact load is input to the pillar structure, the outer panel and the inner panel become deformed in directions in which they move away from one another. As a result, stress concentrates in the flange portions that are the joint portions between the outer panel and the inner panel, so there is room for improvement in terms of maintaining the joint state of the pillar structure during a side impact.